A poly‐γ‐d‐glutamic acid depolymerase that degrades the protective capsule of Bacillus anthracis. Issue 6 (9th February 2014)

• Record Type: Journal Article
• Authors: Negus, David; Taylor, Peter W.
• Is Part Of: Molecular microbiology. Volume 91:Issue 6(2014)
• Page Start: 1136
• Page End: 1147
• Publication Date: 2014-02-09
• Subjects: Molecular microbiology -- Periodicals; 572.829
• DOI: 10.1111/mmi.12523
• Languages: English
• ISSNs: 0950-382X

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>A mixed culture of <italic>P</italic><italic>seudomonas fluorescens</italic> and <italic>P</italic><italic>usillimonas noertemanii</italic>, obtained by soil enrichment, elaborated an enzyme (EnvD) which rapidly hydrolysed poly‐γ‐<sc>d</sc>‐glutamic acid (PDGA), the constituent of the anti‐phagocytic capsule conferring virulence on <italic>B</italic><italic>acillus anthracis</italic>. The EnvD gene is carried on the <italic>P</italic><italic>. noertemanii</italic> genome but co‐culture is required for the elaboration of PDGA depolymerase activity. EnvD showed strong sequence homology to dienelactone hydrolases from other Gram‐negative bacteria, possessed no general protease activity but cleaved γ‐links in both <sc>d</sc>‐ and <sc>l</sc>‐glutamic acid‐containing polymers. The stability at 37°C was markedly superior to that of CapD, a γ‐glutamyltranspeptidase with PDGA depolymerase activity. Recombinant EnvD was recovered from inclusion bodies in soluble form from an <italic>E</italic><italic>scherichia coli</italic> expression vector and the enzyme stripped the PDGA capsule from the surface of <italic>B</italic><italic>. anthracis</italic> Pasteur within 5 min. We conclude from this <italic>in vitro</italic> study that rEnvD shows promise as a potential therapeutic for the treatment of anthrax.</p> </abstract>